Vintage threads from the first ten years

Re: AC30 TB low/high Power Switch

Re: AC30 TB low/high Power SwitchBoy what a dope I was. I completely forgot about the cathode resistor. Absolutely you need to change the cathode value or you'll burn up those bad boys. My guess would be more like 120 -130 ohm. My two EL-84 amps have these in them. But just get the ma @ 40-45 per tube and what ever value it takes to get it there. Depending on the load factor of your tubes you could go from 100-150 ohms. I leave the single resistor in there. I haven't really messed with going multiples. I've had real good luck with the Sovtek EL-84's and when I order them I order nothing above 100 value in there matching system. This allows me to keep the 47-0hm resistor in place, but I've used up to a 62 ohm resistor to maintain the ma. load I prefer. Steve thanks for jogging my memory on the cathode, wouldn't what to screw anybody up!!!